Mounting clip for thrust bearing

ABSTRACT

A compressor assembly comprising a housing having a shaft bore therein, a main shaft positioned for rotation within the shaft bore, at least one roller thrust bearing and a thurst surface bearing clip. The thrust surface bearing clip comprises a first position configured for fixed engagement with the housing and a second portion extending from the first portion and configured for supporting a thurst surface in a position spaced from the rotating shaft, the thrust surface providing a bearing surface for the roller thrust bearing.

RELATED APPLICATIONS

This application is a 371 of PCT/US02/35760 filed Nov. 7, 2002, whichclaims the benefit of U.S. Provisional Patent Application 60/337,757filed Nov. 7, 2001, and U.S. Provisional Patent Application 60/353,417filed Feb. 1, 2002.

BACKGROUND

The present invention relates to thrust bearings. More particularly, thepresent invention relates to piloting arrangements for thrust bearingwashers. The invention lends itself to use in current swashplate airconditioning compressors, but may be applied in compressors of varioustypes and configurations.

The current practice in swashplate air conditioning compressors usesthrust washers on each side of thrust bearings that are piloted on acompressor main shaft. An example of a fixed displacement compressor ofthis type is illustrated in section in FIGS. 1 and 2.

Referring to FIG. 1, the compressor generally comprises a main shaft 10,piston connecting portion 14, piston end portions 16, half ball shoes18, radially loaded roller bearings 20 and 22, thrust washers 24 and 26,roller thrust bearings 28, and swashplate 30 positioned within a housing50. FIG. 2 is a plan view of an illustrative compressor housing 50 withwhich the present invention is utilized. The housing 50 includes a face52 with a shaft bore 54, a plurality of fluid passages 56 and aplurality of piston cylinder bores 58.

As can be seen in FIG. 1, the thrust washers 24 and 26 are piloted offof the main shaft 10. The piloting of the thrust washers 24 and 26 onthe compressor main shaft 10 results in relative rotation between theshaft outer diameter and the bore of one of the washers. Specialfinishing processes for the washer bore (such as fine blanking, forexample) are often used in order to prevent excessive wear between thewasher bore and the shaft.

The current practice with thrust washers piloted on the main shaft alsohinders lubricant from flowing freely to the thrust bearing bore andradially loaded roller bearing. Roller thrust bearings, by their nature,tend to pump lubricant from the bore toward the outer diameter. A clearpath under the thrust washer is desired to allow free pumping action oflubricant through the adjacent radially loaded roller bearing and outthrough the thrust bearing.

SUMMARY

The present invention provides a compressor assembly comprising ahousing having a shaft bore therein, a main shaft positioned forrotation within the shaft bore, at least one roller thrust bearing and athrust surface bearing clip. The thrust surface bearing clip comprises afirst portion configured for fixed engagement with the housing and asecond portion extending from the first portion and configured forsupporting a thrust surface in a position spaced from the rotatingshaft, the thrust surface providing a bearing surface for the rollerthrust bearing.

In at least one embodiment, the thrust bearing surface is provided by athrust washer and the second portion includes at least one tab or lipconfigured to support the thrust washer.

The first portion may include a plurality of housing tabs configured toengage the housing and the second portion includes an annular ringsupported by the housing tabs. The annular ring may include an outersurface that defines the thrust bearing surface or may include at leasttwo opposed washer tabs extend from the annular ring opposite thehousing tabs with the washer tabs configured to support a thrust washerthat defines the thrust bearing surface.

The compressor assembly may further comprise a radial bearing positionedin the shaft bore between the shaft and the housing. In such anembodiment, the radial bearing may include a bearing race with an axiallip extending therefrom such that the bearing race defines the firstportion and the axial lip defines the second portion.

In yet another embodiment, the first portion is defined by a cup bodypress fit in the shaft bore and the second portion is defined by a lipextending from the body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a illustrative prior art compressor.

FIG. 2 is a plan view of a portion of an illustrative compressorhousing.

FIG. 3 is an isometric view of a piloting clip of a first embodiment ofthe present invention.

FIG. 4 is a cross-sectional view of a portion of a compressorincorporating the piloting clip of FIG. 3.

FIG. 5 is a cross-sectional view of a portion of a compressorincorporating a piloting clip included in an alternate embodiment of theinvention.

FIG. 6 is a cross-sectional view of a portion of a compressorincorporating a piloting clip included in yet another alternateembodiment of the invention.

FIGS. 7 and 8 are cross-sectional views of portions at opposite ends ofa compressor incorporating a piloting tab included in yet anotheralternate embodiment of the invention.

FIG. 9 is cross-sectional view of a portion of a compressorincorporating a piloting tab included in yet another alternateembodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described with reference to theaccompanying drawing figures wherein like numbers represent likeelements throughout. Certain terminology, for example, “top”, “bottom”,“right”, “left”, “front”, “frontward”, “forward”, “back”, “rear” and“rearward”, is used in the following description for relativedescriptive clarity only and is not intended to be limiting.

Referring to FIGS. 3 and 4, the piloting clip 60 of a first embodimentof the present invention is shown in conjunction with the compressorassembly including the main shaft 10, shaft bore 54, fluid passage 56,radially loaded roller bearing 20, thrust washers 24 and 26, and rollerthrust bearing 28. The clip 60 generally comprises a cylindrical hoop 62with a plurality of housing tabs 64 and a plurality of washer tabs 66.The housing tabs 64 are configured and positioned to snap intorespective ones of the fluid passages 56 to thereby rigidly mount theclip 60 to the housing 50. The washer tabs 66 are configured to claspthe inner thrust washer 26. Three of each tab 64, 66 are shown, but moreor fewer can be utilized. In such an embodiment, the thrust washer 26 ispiloted by the ring 62 and clips 66 and is spaced from and not inbearing contact with the main shaft 10, see FIG. 4, thereby minimizingwear and allowing lubricant passage.

Two alternative embodiments of the present invention are illustrated inFIGS. 5 and 6. In each of these embodiments, the washer and clip arecombined into a single unit. A plurality of flexible tabs 72 areintegral with and extend from the ring 74. The ring 74 outer surface 75provides a direct bearing surface for the bearing 28. Again, the bearingsurface ring 74 is spaced from and not in bearing contact with the mainshaft 10. A notch 76 may be machined into the housing face 52 (FIG. 8)for receiving the tabs 72 or the tabs 72 can be received directly in theshaft bore 54 (FIG. 9) or the fluid passages 56.

Referring to FIGS. 7 and 8, another alternate embodiment of the presentinvention is illustrated in use at opposite ends of the compressor. Suchembodiment provides an extended lip 84 extending from the race 80 of theradially loaded roller bearing 20. The race 80 is preferably press fitinto the cylinder bore 54. The extended cup lip 84 provides a pilotingsurface for the bore of a thrust washer 26. Again, the washer 26 ismaintained spaced from and not in bearing contact with the main shaft10.

The race 80 may be manufactured as a drawn cup, machined, oralternatively manufactured. The lip 84 need not be annular, but couldconsist of several tabs or the like. A portion 82 of the extending lip84 of radially loaded roller bearing 20 is formed as part of a drawn cupouter race 80 and is offset radially inwardly with respect to thecylinder bore 54 to provide a piloting surface for cage 21.Additionally, a plurality of retention bumps (not shown) may be providedon outer diameter of the extended lip of the radially loaded rollerbearing to serve as an assembly aid to keep the thrust washer in placeon the lip during assembly of the compressor.

Referring to FIG. 9, another alternate embodiment of the presentinvention is illustrated. Such embodiment provides an independentsupport component 90 that is preferably press fit into the shaft bore54. The radially loaded bearing 20 includes a drawn cup race 100 or thelike, however, such race 100 is separate from the support component 90.The support component 90 includes a body 92 that is maintained in theshaft bore 54 and a support lip 94 extending from the body 92. The lip94 provides a piloting surface for the bore of a thrust washer 26.Again, the washer 26 is maintained spaced from and not in bearingcontact with the main shaft 10. The lip 94 need not be annular, butcould consist of several tabs or the like.

1. A compressor assembly comprising: a housing having at least one boretherein; a main shaft positioned for rotation within the bore; at leastone roller thrust bearing; a thrust surface bearing clip comprising: afirst portion configured for fixed engagement with the housing; and asecond portion extending from the first portion and configured forsupporting a thrust surface in a position spaced from the shaft, thethrust surface providing a bearing surface for the roller thrustbearing; and a radial bearing positioned in the shaft bore between theshaft and the housing wherein the radial bearing includes a bearing racewith an axial lip extending therefrom, the bearing race defining thefirst portion and the axial lip defining the second portion.
 2. Thecompressor of claim 1 wherein the lip is an annular lip.
 3. Thecompressor of claim 1 wherein the lip is defined by a plurality ofspaced tabs.
 4. A compressor assembly comprising: a housing having atleast one bore therein; a main shaft positioned for rotation within thebore; at least one roller thrust bearing; and a thrust surface bearingclip comprising: a first portion configured for fixed engagement withthe housing; and a second portion extending from the first portion andconfigured for supporting a thrust surface in a position spaced from theshaft, the thrust surface providing a bearing surface for the rollerthrust bearing; wherein the first portion is defined by a cup body pressfit in the shaft bore and the second portion is defined by a lipextending from the body.
 5. The compressor of claim 4 wherein the lip isan annular lip.
 6. The compressor of claim 4 wherein the lip is definedby a plurality of spaced tabs.